Sang-froid (6)
I believe the answer is:
aplomb
'sang-froid' is the definition.
(synonyms)
This is all the clue.
(Other definitions for aplomb that I've seen before include "Self-satisfied dignity, complacency" , "Pompous dignity or poise" , "Self-satisfied assurance" , "Self-satisfied poise" , "coolness is required" .)